Continuous casting machine



Sept. 15, 1970 wo uM ET AL 3,528,487

CONTINUOUS CASTING MACHINE Filed June 5. 1967 '7 Sheets-Sheet 1' p 15,1970 J. N. WOGNUM ETAL 3,528,487

' CONTINUOUS CASTING MACHINE 7 Sheets-Sheet 2 Filed June 5. 19.67

In 1/ e7z/Z0ns' mes/VT Wqgnum P 15, 1970 J. N. WOGNUM El'AL 3,528,487

J. N. WOGNUM ETAL 3,528,487

CONTINUOUS CASTING MACHINE Sept. 15, 1970 Filed June 5. 1967 s Q 7 w J0, a r w M M 3 w w W a rm m .59 m WM? m 7 m m l w E 3 W lv 1 w 1/ M a 5if 0 a a 6 a w M L 4 w 5 N\\\\\\\\hi\\i\\\\\\\\\ y 1% w a I. I- l 3 0 aw w Sept. 15, 1970 J. N. WOGNUM ETAL 3,528,487

CONTINUOUS CASTING MACHINE '7 Sheets-Sheet 5 Filed June 5, 1967 yen Zorafines A! 'Waymmz/ affair? L. Wzmr EmiZ5z'mz'c2 (5/ lww PPMCMA Sept. 15,1970 J. N. WOGNUM EI'AL CONTINUOUS CASTING MACHINE 7 Sheets-Sheet 6Filed June 5, 1967 1 r IA Sept. 15, 1970 J. N. WOGNUM ETAL 3,528,487

CONTINUOUS CASTING MACHINE Filed June S 196? 7 Sheets-Sheet 7 ("H-F1 T I,14 l I l I ll ,71.

uww QQ MI United States Patent ice 3,528,487 Patented Sept. 15,, 19703,528,487 CONTINUOUS CASTING MACHINE James N. Wognum, Emil Simich, andAlvin L. Winkler, Chicago, Ill., assignors to Interlake SteelCorporation, Chicago, 11]., a corporation of N ew York Filed June 5,1967, Ser. No. 643,562 Int. Cl. B22d 11/00 US. Cl. 164280 8 ClaimsABSTRACT OF THE DISCLOSURE Apparatus for continuous casting of metalhaving a cavity formed by a plurality of flexible mold sections whichminimize the problems of mold warpage by thermal expansion. Resilientbackup for the mold sections for controlling mold cavity contour,improved mold section operating means and arrangement therefor is alsoprovided.

This invention relates to the art of continuous casting and particularlyrelates to improvements in continuous casting in a machine of thevibrating mold type as, for example, shown in U.S. Pat. No. 3,075,264 inthe name of James N. Wognum.

The type of continuous casting machine is one having a cavity extendinglongitudinally through it, the cavity being open at its opposite endsand formed by the inside surfaces of a plurality of vibrating moldsections located around the cavity, one of the open ends of the cavitybeing the receiving end through which molten metal can be introducedinto the cavity and the other end being for discharge of the metal afterit is solidfied as a casting as it passes through the cavity. The moldsections may be vibrated in closed orbital paths to drive the castingbeing formed in the cavity through the cavity.

One of the problems associated with the operation of this type ofcontinuous casting machine is created by thermal expansion of the [moldsections which creates an undesirable warping of the mold sectionswhich, if permitted, can bind the machine and make it inoperative.Previously, solution of this problem has been sought by employing largermasses of metal for the mold sections to counteract the warpage byreliance on the strength of the extra metal. Experience shows thatobjectionable differentials in expansion of different parts of the moldsections due to the various temperature differentials is not arrested bythe use of the added metal. Instead, applicant has discovered far morecan be accomplished by the use of flexible and resilient mold sectionsof relatively small cross section and of minimal metal mass. By the useof flexible mold sections, applicant has found that the mold sectionscan be retained in their proper shape without warpage, even thoughthermal stresses are present. Therefore, it is the principal object ofthis invention to provide an improved continuous casting machineemploying flexible mold sections of relatively small mass which,although subject to thermal stresses due to temperature differentials,can be easily retained in a proper configuration without objectionablewarpage.

In order to accomplish the aforesaid object, it is another object of theinvention to provide resilient backing means for each mold section whichcan be used to apply forces along the mold sections to keep them intheir proper configuration when subject to the tendency for warpage dueto the thermal stresses.

This can be accomplished by employing resilient means, such as springs,or by means of inflatable cushions, as another example, and in otherways.

One of the current problems with continuous casting machines, alsoinvolving thermal considerations, is that there is a tendency for thecasting to shrink away from the internal side walls of the mold as thecasting solidifies. The result is that the casting portions out ofcontact with the mold are difficult to cool properly. For this reason,even though coolant is circulated through openings in the mold itself,the lack of contact between the casting and the mold reduces theconduction of heat from the casting to the mold where the heat can beremoved by the coolant. In fact, this separation of the casting from themold leaves an air or gas space which is a poor conductor of heat whichacts more like a heat insulator. For this reason, it is common to employwater spray cooling on the portions of the casting exiting from themold. Water spray cooling is in some instances objectionable because itdoes not permit the casting to be transported directly from the moldinto a controlled atmosphere for purposes of retaining a bright finishon the surface of the casting. In order to overcome this problem, it isanother object of this invention to provide a mold having flexible moldsections which can be insured of ,contacting the external wall surfacesof the casting so that efficient transfer of heat can be effected fromthe casting through the internal walls of the mold and to the coolantcirculating through the mold without necessarily requiring additionalexternal cooling, as by water spray cooling, for example.

Especially when casting high alloy metals, it is desirable to employmolds of long length in order to insure that sufficient wall portions ofthe casting freeze thick enough so that the casting skin does not breakand allow hot metal from the core of the casting to pour out through itwhich is a dangerous condition and one which causes a poor surfacecondition. With high alloy metals, the freezing range of the metal isvery wide and this is the reason why more mold time is desired. However,in other molds, as the casting cools, it shrinks away from the mold wallsurface and the cooling by lack of contact with the mold sectionsbecomes inefficient. In fact, it seems that the mold for coolingpurposes, should be no longer than the length which remains in contactwith the casting. Thereafter, since the mold is very ineffective forcooling by conduction, it is desirable to employ a Water spray directedonto the casting emerging from the mold section. But, this suggestsshortening the mold when the high alloy materials indicates the oppositerequirement that the mold should be longer. Due to the increasedassurance of proper cooling in the mold for its entire length because ofthe improvements of this invention, it is another object of theinvention to provide an improved mold which can be made in longerlengths to accommodate those situations requiring the longer lengths.

Another object of the invention is to provide flexible mold sectionswhich are connected only at one end to the mold section supportstructure. This permits the mold sections to freely lengthen and shortenlongitudinally as heating and cooling occur. This further minimizes thestresses due to temperature differentials causing thermal expansion andcontraction.

In order to maintain high heat transfer through the mold sections alongtheir lengths, efforts have been made to provide special contours forthe mold walls according to the expected thermal shrinkage of thecasting as it progresses through the mold. However, this has beenrelatively unsuccessful because different contours are required for eachdifferent metal used because the different metals expand or contract bydifferent amounts when subject to the same temperature differentials.Further, if advancement speed of the castings through the mold varies,each different speed suggests that a different contour be required. Itis an object of this invention to provide a flexible mold section sothat the mold can be employed with many different metals of differentphysical thermal properties and be operated at many different speedswithout requiring any special predetermined coutouring of the moldsections to overcome difliculties created by uneven thermal expansionand contract and which can be adjusted while operating to cause the moldsections to deflect into proper contours according to the actualshrinkage contours of the castings.

It is another object of the invention to provide an improved modulartype of construction for a continuous casting machine involving acasting unit module having all of the basic casting components containedwithin it which lends itself to ready insertion or removal in acontinuous casting system and which has its major moving parts housed indust-proof enclosures.

It is another object of the invention to provide a modular continuouscasting machine having an improved radical construction readilypermitting basic components to be employed for changeover to castdifferent sizes of cross section of castings.

It is another object of the invention to provide a continuous castingmachine which can be assembled and disassembled readily for easy accessto all parts of it.

It is still another object of the invention to provide such a machinewhich has an improved driving arrangement for causing the mold sectionsto vibrate through their orbital paths, including suitable vernieradjustment means for fine adjustment of the spacing of the mold sectionsrelative to each other.

It is another object of the invention to provide improved linkagemechanism in the driving means for the mold sections, which linkageprovides the desirable vibratory paths for the mold sections.

It is also another object of the invention to provide a resilient takeupfor any play existing between the operating shafts and the bearingssupporting them so that the linkage mechanisms employed are withoutlooseness, even though there are no precision fits at the bearingconnections.

Because it is desirable to have the individual mold sections fluidcooled by passing the coolant through bores extending internally throughthe mold sections and to have the mold sections easily removable fromthe casting machine assembly, it is necessary to have quick disconnectsbetween the fluid coolant inlets and outlets to the mold sections. It isan object of this invention to provide improved disconnects which eitherautomatically connect or disconnect the fluid coolant outlets and inletsor which can be operatively connected or disconnected to the moldsections. The means for accomplishing this can be by use of a connectingtubular piston which abuts against the mold section by means of springpressure to close the connection or by means of fluid pressure.

It is a further object of the invention to provide improved cornerinserts mounted between adjacent mold sections for the purpose ofminimizing leakage of liquid metal from the casting at the corners ofthe mold while the casting is propelled through the mold. These improvedcorner inserts are made flexible and provided with relatively flexiblebackings which may be further backed by resilient members urging thecorner inserts into intimate contact against the mold sections andthereby seal the flow of liquid metal from between the interfacesadjacent mold sections and corner inserts to follow the changeablecontours of the flexible mold sections.

It is another object of the invention to provide certain proximitydevices behind each mold section for the purpose of indicatingexternally of the mold that the contacting mold surfaces are in completecontact with the casting surfaces. These proximity or sensing devicesprovide sig- 4 nals for detecting and indicating this information whilethe mold is in operation. This is important because it is necessary foraccuracy that the mold sections be adjusted dynamically during thecasting operations so that the mold sections are accurately relocated tothe changing sizes of shrinking or expanding portions of the movingcasting while the casting is being progressively cooled.

It is another object of this invention to provide a continuous castingmachine of the type described which has adjustable means at both theupper and lower ends of each mold section to allow for radial adjustmentof either of the mold sections as required. This allows the lower endsof the mold sections to be radially shifted relative to the upper endsof the mold sections in order to compensate for the shrinkage of thecasting as it solidifies.

It is another object of the invention to provide retainer blocks for themold sections which are relatively rigid and made of material withrelatively low susceptibility to thermal warpage at the operatingtemperatures of the machine. This provides relatively rigid backup meansfor the mold sections even though the mold sections themselves areflexible. It is important that the backup means for the mold sections berigid in order to provide dimensional stability to the apparatus.

Other objects and advantages of the invention should become apparentupon reference to the accompanying drawings in which:

FIG. 1 shows a preferred embodiment of continuous casting machine madeaccording to the invention in the form of a modular unit;

FIG. la shows a cross-sectional view of a spring retaining meansemployed with the unit of FIG. 1;

FIG. 2 shows a horizontal cross section of the major functional parts ofthe mold portion of the preferred embodiment of the continuous castingmachine shown in FIG. 1;

FIG. 3 shows a perspective view, primarily from the rear, of a moldsection support and the mold section it supports;

FIG. 4 shows a perspective view, primarily of the front portion of theapparatus shown in FIG. 3;

FIG. 5 shows a perspective exploded, partially cutaway and partialsectional view of a mold section and its related components separatefrom its support indicated in FIGS. 3 and 4;

FIG. 5a shows a cutaway sectional view of an alternate construction ofmold section to that shown in FIG. 5;

FIG. 5b shows a partially cutaway sectional and exploded perspectiveview of one form of resilient cushion employed as a backup for a moldsection;

FIG. 50 shows a cutaway portion in section of an alternative form ofresilient backup means for mold section.

FIG. 5a' shows a cutaway portion in section of still another alternativeform of resilient backup means.

FIG. 52 shows a cutaway portion in section of still another alternativeform of resilient backup means.

FIG. 6 shows a partially cutaway sectional and perspective view of alinkage box, including the linkages and drive shafts for vibrating amold section;

FIG. 6a shows a sectional view along the line 6a-6a of FIG. 6;

FIG. 7 shows a partially exploded perspective cutaway and sectional viewof a corner insert and mounting structure for it; and

FIG. 7a shows a partially cutaway and sectional view I of the lowerportion of the apparatus shown in FIG. 7.

The preferred embodiment of the invention shown in FIG. 1 consists of anentire continuous casting machine 1 containing all of the basiccomponents of the machine in a modular unit. The machine is providedwith an upper rigid plate 2 and a lower rigid plate 3 which are spacedfrom each other and extend in planes parallel to each other. The upperplate is provided with four grooves 4 extending at right angles to eachother and radially outward from the center line 5 of the castingmachine. The lower plate 3 is also provided with four radially extendinggrooves 6 which extend directly opposite the grooves 4. These grooves 4and 6 function as keyways for relatively long rectangular keys 7 (FIG.6) which are also keyed into grooves 8 provided in the upper and lowersurfaces 9 and 10 respectively, of a linkage box 11. In the particularembodiment shown, there are four linkage boxes 11 because there are fourmold sections operated. Of course, if fewer or more mold sections areemployed, there will be required a linkage box 11 for each mold sectionto be vibrated.

These linkage boxes 11 are suitably positioned and located radiallybetween the upper and lower plates 2 and 3 and then secured in placesuitably by means of screws 12 extending through the plates 2 and 3 andthe keys 7 and into the upper surfaces 9 of the linkage boxes 11.

Surrounding each linkage box 11 is a mold section support 13 which isdriven by means of the linkage and shafts contained therein, ashereinafter more fully described. Each of the mold section supports 13supports a mold section 14. Each mold section support 13, particularlyshown in FIGS. 1, 3 and 4, consists of a longitudinal frame member 15joined to two side plates 16.

The side plates are substantially triangularly shaped andprovided with arear brace 17 bridging between them. The frame member .15, the sidewalls 16 and the rear brace 17 are suitably connected by welding orscrews into an integral box-like shape. The upper regions of the sideplates 16 are provided with round openings 18 and the lower portions areprovided with other round openings 19. As hereinafter described, theseopenings 18 and 19 provide journals for the ends of certain shafts whichare driven through orbital paths to cause the mold section supports 13to move through corresponding orbital paths.

In order for the machine to cast a casting having a substantially squarecross section, the principal functional parts of the machine arearranged as shown in FIG. 2. Four mold sections 14 are alternatelypositioned with mold sections 14 in pairs facing each other so that theinside surfaces 14a of the four mold sections 14 face in- Wardly towardthe center of a cavity formed by the mold sections 14 through which thecasting 20 is propelled by the mold sections 14. As previouslymentioned, each mold section 14 is supported by a frame member 15. Eachof these frame members 15 is provided with a T-shaped groove 21extending for its entire length. This groove 21 is bounded by twoinwardly extending lips 22 having rear surfaces 23 against which edgeflanges 24 of each mold section can abut as a limit on the movement ofthe mold section inwardly toward the center line of the mold cavity. Arear wall 25 of the frame member 15 provides the bottom surface of theT-shaped groove 21.

In the embodiment shown in FIG. 2, each mold section 14 is spaced fromthe rear wall 25 by means of an inflatable cushion or pillow in the formof a tube 26 which can be inflated to bear against the mold section 14and urge it inwardly toward the center of the mold cavity. To act as aspacer shield and partial insulator between the mold section 14 and theinflatable cushion 26, a flat stainless steel strip 27a is positionedbetween the rear wall 14b and the front wall 26a of the cushion 26.

The purpose of the inflatable cushion 26 is to provide a continualpressure substantially uniformly along the entire length of a moldsection 14 to counteract any tendency of the mold section .14 toobjectionably bow or otherwise warp and to allow the mold section 14 tobe displaced relative to its frame member 15 when the inside surfaces14a of the mold sections are brought firmly into contact against thesurface 20a of the casting 20.

In the copending application of James N. Wognum, Ser. No. 601,738, filedDec. 14, 1966, there is disclosed the use of corner inserts forminimizing leakage at the corner regions between the mold sections 14.In the embodiment shown in FIG. 2, these corner inserts 27 are of 6substantially square cross section and positioned between the side wallsof adjacent mold sections 14 to bridge the corners 28 of the casting 20.Similarly, to maintain the corner inserts 27 in position, a T-shapedbacking plate 29 is provided with its leading edge abutting against theinsert 27. This backing plate has two shoulder surfaces 30 which arelimited in their movement toward the center of the mold cavity by othershoulders 31 on a frame member 32 which are surfaces of a T-shapedgroove 33 extending longitudinally along the frame member 32. Providedin the groove 33 is another inflatable cushion or tube 34 which, wheninflated, bears against a flat retaining strip 35 which in turn pressesagainst the rear surface of the backing plate 29 to urge the backingplate into contact with a corner insert 27 The corner inserts 27 arepreferably made of small cross section, as indicated, and of a materialsuch as graphite which has a smooth surface and is a good heatconductor.

One embodiment of the mounting construction for a mold section is shownin FIG. 5. The frame member 15 is also substantially T-shaped withflange portions 15a providing the means for securing the side walls 16thereto. The central region of the frame member 15 is pro vided with abore 36 through which coolant fluid is introduced for maintaining thetemperature of the mold section 14 at its proper level. Secured to therear lower face of the frame member 15 is a manifold 37 which carriessuitable openings for the proper introduction of coolant and air underpressure. In the embodiment shown in FIG. 5, the manifold has an opening38 leading to the bore 36, an opening 39 leading to the bore 40 and anopening '41 leading to the bore 42. There is also an opening 43 whichleads to a bore 44 which is a conduit for two wires 45 leading to andfrom a proximity device 46, as hereinafter more fully described,

The same coolant that is introduced into the bore 36 returns after ithas passed through the upper length of the frame member 15 and throughopenings 14c extending through the mold 14 until it reaches the bore 42and passes out through the opening 41 in the manifold 37.

Air under pressure is introduced through the opening 39 into the bore 40where it passes through the central bore 47 of a tube 48 around whichthe tubular stem 49 of the inflatable cushion 26 is positioned to allowthe cushion 26 to be inflated. This provides the resilient backup forthe mold section 14, as previously described upon reference to FIG. 2. Asuitable packing plug 50 is provided in an enlarged portion 51 of thebore 40 in order to suitably retain the pin 48 and the tubular stem 49.

As indicated in FIG. 5, the inflatable cushion 26 extends for asubstantial distance from adjacent the bottom of the frame member 15 toa location indicated at 52. Also, the mold section 14 is unrestrained inlongitudinal sliding movement relative to the frame member 15 except atthe upper end of the frame member 15 where suitable retaining means isprovided from which the mold section 14 is hung. This retaining meansconsists of a retainer block 53 which is provided with a hollow bore 54which connects with the bore 36 of the frame member 15 at an abuttingregion 55. The bore 54 has a front surface 56 which closely abuts therear surface 14b of the mold section 14. A transverse rectangularlyshaped key 57 extends in suitable keyways 58 and 59 provided in the moldsection 14 and the retainer block 53 respectively. In order to assemblethe mold section into its proper location, the retainer block 53 iskeyed to the mold section 14 and manually together they are lowered intoplace from the upper end of the frame member 15. After positioning, setscrews 60 threaded through openings in the upper rear portion 15b of theframe member 15 are tightened against the rear wall 53a of the retainerblock 53. In addition, an upper end cap 61 is positioned against theupper end of the retainer block 53 and upper end of the portion 15b ofthe frame member 15 and held in place by means of screws 62 as a furtherretaining means for the retainer block 53.

The bore 54 of the retainer block 53 is L-shaped to lead into the upperends of the bores 140 of the mold section 14 so that there can be acomplete circuit of flow of coolant through the frame member 15, theretainer block 53 and the mold section 14.

At all necessary junctures between the parts where there is fluid flowof coolant, suitable O-rings are provided to prevent leakage. Forexample, an O-ring 63 is provided at the upper end of the assemblybetween the bore 54 of the retainer block 53 and the bores 140 of themold section 14.

With the arrangement shown, it should be apparent that the mold section14 is truly hung from the upper end of the frame member 15 and it isfree to expand and contract longitudinally as it is guided in theT-shaped opening 21 of the frame member 15. This lack of restraint,minimizes the tendency to bow or warp which is evident in moldconstructions having fully restrained mold sections.

In order to maintain a leakproof seal at the lower end of the moldsection 14 which is free to deflect radially of the machine, a plunger64 is provided in the bore 42. The plunger 64 is provided with a helicalspring 65 encircled about it which reacts against a Wall 66 of the framemember 15 and an annular flange 67 on the plunger 64. The spring 65urges the plunger toward the opening 41 in the manifold 37. When themold section 14 is properly positioned, air is supplied through the bore40 to inflate the inflatable cushion 26. Simultaneously, the air isdirected through another small bore 68 leading to an annular region 69in the rear of the annular flange 67. The air pressure urges the plunger64/ in a direction away from the opening 41 in the manifold 37 andtoward the mold section 14. The end of the plunger 64 is provided withan O- ring 70 which is thereby urged into intimate contact around theopenings leading to the bores 14c of the mold section 14 to therebyprovide a fluid type connection. When it is necessary to remove a moldsection 14 for replacement or repair, the air pressure is removed fromthe bore 40 which relieves the pressure in the inflatable cushion 26 andagainst the annular flange 67 of the plunger 64 so that the springreturn relieves the pressure of the O-ring 70 from against the moldsection 14. At that time, upon suitable loosening of the set screws 60and the screws 62, the mold section 14 can be removed from the upper endof the assembly.

The proximity device 46 is one which provides a signal in the form of achange in D.C. voltage when there is a change in the presence of metaladjacent the front surface 46a of a detector 46b. A suitable proximitydevice is one which can be purchased from Bently Nevada Corp., Box 157,One Airport Road, Minden, Nev. The change in presence of metal is sensedby the detector 46b which is connected by the wires 45 to a detectordriver 46c which has a D.C. voltage output which varies with the changein presence of metal at the detector. The variation in voltage outputcan be visually indicated on a meter 46d.

A proximity device 46 is provided in each mold section support 15 andthere is a corresponding detector driver 46c and meter 46a for eachproximity device 46. In operation, the mold sections 14 are placed intheir orbital vibratory paths by means of their mold section supports 15suitably driven through the drive systems mentioned by means of themotors 140. With no casting metal present, the inflatable tubes 26 keepthe mold sections 14 pressed radially toward the center of the mold sothat the edge flanges 24 of each mold section abut against the rearsurfaces 23 of the inwardly extending lips 22 on the mold sectionsupports 15. As casting begins, the metal casting travels through themold cavity of the machine. The metal adjacent the top of the mold fillsthe cavity and presses against the inside surfaces 14a of the upper endsof the mold sections 14. However, ordinarily the casting shrinks as itprogresses through the mold cavity so that there is a tendency for themold portions of the inside surfaces 14a of the mold sections 14 to beout of contact with the casting at its lower end, To overcome this, theeccentric adjustments are made on the pins 130 to adjust the links 133radially inwardly toward the center line 5 of the mold cavity until theinside surfaces 14a of the mold sections contact the casting. Theindication that contact has been made by a mold section against thecasting is when a cyclical pulsing of increasing and decreasing voltageappears on the meter 46d. This signifies that the mold section 14 iscyclically pressing against the casting as its edge flanges 24reciprocate away from and toward the lips 22 of the mold section support15. In order to make the proper adjustment, the eccentrics on the pins130 are adjusted until the cyclical voltage variations on the meters 46dare pronounced and then the eccentric adjustments are made until thecyclical voltage variations are minimal. That point is reached when theedge flanges 24 of the mold sections 14 no longer reciprocate back andforth away from the lips 22 of the mold section supports 15.

The proximity device 77 indicated in FIG. 5a is of the same kind asproximity device 46 and it is suitably con nected by Wires to a detectordriver and a meter similar to items 460 and 46d for proper operation.Its adjustment is in an identical manner for the mold section 72 as forthe mold section 14 when employing the proximity device 46.

As an alternate to the mold section support indicated in FIG. 5, thereis another embodiment shown in FIG. 5a. There are basically the samecomponents but their structures are somewhat different. There is amanifold 71 corresponding to the manifold 37, mold section 72corresponding to the mold section 14, a frame member 73 corresponding tothe mold section 14, a frame member 73 corresponding to frame member 15,an inflatable cushion 74 corresponding to inflatable cushion 26, a bore75 through the frame member 73 corresponding to bore 36, a bore 76corresponding to bore 40, a proximity device 77 corresponding to thesame device 46 and a plunger 78 corresponding to plunger 64. There isalso a spring 79 which acts reversely of the spring 65. Spring 79 urgesthe plunger 78 toward the mold section 72 rather than away from it, asdoes spring 65.

The lower end of the mold section 72 is provided with a sloped surface80 which reacts against the leading sur face 81 of the plunger 78 whichis urged against the mold section 72. The plunger surface 81 is likewisedirected along the same angular inclination as the surface 80 and theplunger 78 is guided in a bore 82 which is similarly sloped and whichcarries the spring 79. With this construction, as the mold section 72 islowered into position, its lower surface 80 cams against the surface 81of the plum ger 78 and the plunger 78 remains in contact with the moldsection 72 by the action of the spring 79, regardless of the relativeposition of the mold section 72 radially relative to the center of themold. This system of maintaining of fluid-type connection at the lowerend of the mold section 72 has the advantage that no air pressure isrequired. Instead, reliance on a spring is all that is necessary. v

Another significant difference is the manner in which the mold section72 is suspended from the upper end of the assembly. The upper end of themold section 72 is provided with a keyway 83 which engages with ashoulder 84 of a retainer block 85. The retainer block 85 has a slopedbottom surface 86 which mates with a correspondingly sloped surface 87at the upper end of the frame member 72. For assembly purposes, the moldsection 72 is assembled to the retainer block '85 by engaging theshoulder 84 with the keyways 83. In assembled form the mold section 72is then lowered into a T-shaped slot corresponding to the slot 21 in theframe member 15. Another surface 86 bottoms on the surface 87 andfurther downward urging of the retainer block 85 causes tighterengagement of the shoulder 84 in the keyway 83. This provides an insuredtightness. Then, with the retainer block 85 and the mold bar 72 inposition, an end 88 is positioned above the retainer block 85 andsecured in place by means of screws 89 extending through the cap 88 andthe frame member 73.

Although the inflatable cushion 26 can be made of molded plastic orrubber in a single piece, the inflatable member 74 is shown to be of adifferent construction. As indicated in FIGS. a and 5b, it consists of aflattened tube 74a as a main body portion which can be made of thin wallbrass tubing or other metal. The ends of the tube 74a are provided withplugs 74b which are preferably made of brass and silver soldered inplace. Also soldered at the lowerend of the tube 74a is a sleeve 740which is provided with a central bore 74d which leads to an opening 74ein the wall of the tube 74a so that air under pressure can be introducedinto the tube 74a. Because of the limited travel required of theexpanding walls of the tube 74a, this particular structure is quitesuited for the purpose intended, especially because of its greaterdurability over the inflatable cushion 26 made of rubber or plastic. Inaddition, as a suitable shield for the inflatable cushion 74, flatstrips 90 and 91 of stainless steel are positioned along oppositesurfaces of the tube 74a.

Another important feature of the mold section 72 is the use oftransverse grooves 92 cut into the mold section 72. The purpose of theseis to make the mold section 72 as flexible as possible so that minimumforces are re quired to keep the mold section 72 free of an undesirablewarpage from thermal stresses and to allow the mold section to conformto the shrinkage contour of the surface of the casting.

With reference to FIGS. 7 and 7a, each of the corner inserts 27 issupported in a manner similar to each of the mold sections 14 or 72, aspreviously described with reference to FIG. 2. Further, althoughinflatable cushion 34 shown in FIG. 2 can be made of rubber or plastic,it can also have a construction similar to that which is shown in FIG.5b for the inflatable cushion 26.

As indicated in FIG. 7, the backing plate 29 or the corner insert 27 canbe provided with transverse slots 93 which are intended to make thebacking plate 29 more flexible. There is no equivalent of the backingplate 29 shown for the support of the mold sections 14 or 72. Theseslots 93 extend to intersect circular bores 94 extending transverselythrough the backing plate 29 for the purpose of minimizing stressconcentrations which can lead to cracking. The upper end of the assemblyis provided with an end cap 95 which is held in place on the framemember 32 by means of two screws 96. This end cap 95 keeps the backingplate 29 securely positioned. This arrangement makes it very simple toreplace corner inserts 27 which may become damaged or broken.

Keyed to two projecting key portions 97 and 98 at the rear of the framemember 32 are two brackets 98 and 99 which are provided with mountingholes 100 and 101 which permit securement to the upper and lower plates2 and 3 of the machine.

As indicated in FIG. 7a, there is shown the details of the lower portionof the assembly for holding corner insert 27. The bracket 99 is securedto the frame member 32 by means of two screws 102 and 103 and a locatingpin 104. The screw 102 and the locating pin 104 extend through anothermounting bracket 105 which has a vertical wall 106 against which theframe member 32 rests. An upper Wall 107 of the mounting bracket 105provides support for a cover plate 108 secured to the bottom end of thebacking plate 29 and the backing plate 108 also supports the lower endof the corner insert 27. The screw 103 passes through a threaded hole109 which is sloped downwardly so that the end of the screw 103 canreact against a ,sloped surface 110 on the frame member 32 to therebyfirmly retain the assembly by urging the frame member 32 snugly againstthe vertical wall 106 of the 10 mounting bracket 105. The inflatablecushion 26 is of the same general construction as the cushion 741: shownin FIG. 5b, as employed as a backing for the mold sections 14 or 72.However, the other type made of rubber or plastic can also be employed.However, as shown in FIG. 7a, the lower end of the inflatable cushion 26is provided with an inlet conduit 111 which is preferably silversoldered to the cushion 26 and which permits the inflating .of it with asource of pressurized air. In addition, the

backing plate 29 shown in FIG. 7a is provided with additional slots 112which can be added along the front edge of the backing plate 29 tofurther increase the flexibility of the backing plate 29 to furtherminimize the forces required to resist undesirable Warpage ordeformation due to thermal stresses.

As shown in FIG. 6 and partially in FIG. 1, the linkage box 11 has twoside walls 11a which are joined with upper wall 9, the lower wall 10 andfront and back walls 11b and to provide an entirely enclosed containerfor the linkages required to properly actuate the mold sections.

Within each linkage box 11 is a main driven link 113 which is journaledat its lower end 114 on an eccentric portion 115 of a shaft 116. Theupper end of the link 113 is pivoted on a pin 117 to one end 118 of alink 119. The other end 120 of the link 119 is journaled on a shaft 121whose outer ends on either side of the link are journaled in a fixedposition in the side walls 11a of the linkage box 11. Adjacent to theupper end of the link 113 is another shaft 122 which extends through theside walls 11a of the linkage box 11 clear of any contact with thelinkage box 11 and journaled into the openings 18 previously mentionedas provided in the side walls 16 of the mold section support 13.Suitable bushings or other bearings can be provided for increasingdurability of these bearing connections.

Intermediate between the upper and lower ends of link 113 is another pin123 extending through the link 113 with its ends journaled in one end124 of a link 125 whose other end 126 is journaled on a pin 127 mountedat the upper end 128 of a link 129. The link 129 extends substantiallyparallel to the link 113 and has its lower end provided with a pin 130'whose ends are journaled in a fixed position in the side walls 11a ofthe linkage box 11. Slightly above the lower end of the link 129 anotherpin 131 is provided in the link 129 with its ends extending laterallytherefrom and journaled to one end 132 of another link 133 whose otherend 134 is provided with a shaft 135 extending laterally from both sidesof the link 133 and through the side walls 11a of the linkage box 11without any contact thereof and journaled in the holes 19 previouslyreferred to in the side wall 16 of the mold section support 13. Suitablebushings or other bearing means can be provided in these regions fordurability, similar to What are provided for shaft 122.

Two spacers 136 and 137 are provided between the side walls 11a of thelinkage box 11 and they are suitably secured in place by screws or otherfastening means.

With the linkage arrangement disclosed, it should be apparent thatrotation of the main shaft 116 causes its eccentric portion 115 toprovide a vibratory orbital movement of the lower end 114 of the link113. This orbital motion is imparted to both of the shafts 122 and 135.Such motion is delivered to the shaft 122 directly through the link 113.Such motion is delivered to the shaft 135 through the link 125, the link129 and the link 133. Suitable variations in the positions of the shafts122 and 135 relative to the linkage box 11 can be obtained by providingthe shafts 121 and 130 with adjustable eccentric bearing supports forthe end portions of the links 119 and 129 they support which shafts 121and 130 are adjustable by rotation. The purpose of these adjustments isto vary the location of the shafts 122 and 135 relative to the linkagebox 11 in order to vary the positioning of the mold sections 14 or 72 asdesired. By having varia tions on both shafts 121 and 130, it ispossible to vary the in and out positions of either the upper end orlower end of each mold section 14 without any significant change in thelocation of the other end not adjusted. In FIG. 6a, a suggested mountingfor eccentric adjustment of the shaft is shown. The shaft 130 isprovided with a central portion 130a which is eccentric of the centerline 13% of the shaft 130. Two reduced portions 1300 and 130d of theshaft 130 are journaled directly in bearings 130a and the free end 130extends beyond the portion 1300. A nut 130g is threadably secured on athreaded portion 13011 of the shaft 130 and ordinarily tightened againsta shoulder 1301'. The eccentric portion 130a is mounted in a lowerbearing 130i which journals it to the link 129. When it is desired toadjust the spacing of the shaft 130, the nut 130g is loosened and theshaft 130 is rotated by external access to the end 130f. The shaft 130is rotated until the eccentric portion 130a rotates sufficiently toproperly adjust the position of the bottom end of the link 129. Thisadjustment of the bottom end of the link 129 in turn adjusts theposition of the link 133 and, in turn, that of the shaft 135. Similarly,the shaft 121 can be provided with an adjustment identical to that asshown for shaft 130 in FIG. 6a in order to adjust the position of thelink 119 to, in turn, adjust the position of the shaft 122.

Another manner of acquiring some adjustment, not indicated, is toprovide each link 119, 125 and 133 with a turnbuckle centrally locatedon each one. Rotation of the turnbuckle can provide lengthening orshortening of the link desired. The advantage of the eccentricadjustment is that it can be arranged for external adjustment while themachine is operating.

The main shaft 116, as indicated in FIG. 1, is coupled at 138 to thedrive shaft 139 of a driving motor 140. In the arrangement shown, thereare four linkage boxes 11 because there are four mold sections shown asrequired to be driven and, likewise, there are four motors 140 fordriving them. The motors are of a standard synchronous type so that theproper phase relationship of the motion of the mold sections can bemaintained at all times during the operation of the device.

In order to maintain lateral stability of the mold sections, the moldsection supports 13 are held in position by links 141 and 142. Link 141extends between a side wall of the mold section support 13 and a bracketsecured to the undersurface of the bracket plate 2. Link 142 connectsbetween a side wall of the mold section 13 and a plate 143 whichsupports one of the motors 140. These links 141 and 142 are journaled attheir ends to allow for the movement of the mold section supports 13 asthey move through their orbital vibrations.

In order to provide a tight, rattle-free movement of each mold sectionsupport 13 without the use of precision bearing mounts, a takeup device144 is provided on each rear brace 17 of each mold section support 13.Its components are particularly shown in FIG. la where each takeupdevice 144 has an outer cup-shaped shell 145 which is welded directly toa rear brace 17. Contained within a cavity 146 of the shell 145 is aplunger 147 which bears against the outer end of a coil spring 148having an inner end which bears against the outer wall 110 of a linkagebox 11. Secured by screws 149 to the outer wall 110 is a spring endpositioning plate 150 provided with a circular opening 151 of slightlylarger diameter than that of the spring 148 so that the end of thespring 148 can be contained in this opening 151. The outer end of theshell 145 is provided with a threaded opening 152 connected with anadjusting screw 153 which can be threadably adjusted along the opening152 to provide for more or less compression of the spring 148 andthereby adjust the reaction forces of the spring 148 between the moldsection support 13 and the linkage box 11. The purpose of this springpressure is to bias all of the linkage shaft trunnion connections in onedirection to remove any slack or looseness and thereby create a tightoperating condition between the moving parts. This 12 maintains thedesired tight condition even though the trunnion connections may not beprecision fit and permits the use of standard bearings to minimize thecost of the installation.

Further, the fact that the linkages and mechanisms associated therewithare contained entirely within the linkage boxes 11 without any externalexposure, there is excellent protection for these parts from dust ordirt in the area where the machine is to be used.

In the operation of the device, the synchronous motors 140 are operatedto rotate the drive shafts 139 and cause the mold sections 14 or 72 tovibrate through small orbital paths. Experience indicates that thebottom radial amplitude of vibration and the longitudinal amplitude ofvibration relative to the longitudinal axis 5 of the mold can vary overa wide range with satisfactory results, and the operating frequency canalso vary in a very wide range up to 50,000 cycles per minute and more.The amplitude selected are dependent upon the frequency chosen and thecombination of amplitudes and frequency are selected on the basis of thedesired surface condition sought on the casting and the speed of travelof the casting through the mold. Ordinarily, the opposite positionedmold sections 14 are vibrated approximately 180 degrees out of phasewith the other two mold sections. In this manner, there aresubstantially always two mold sections approaching the casting 20 whilethe other two mold sections are moving away from the casting 20. Thistype of movement is fully described in U.S. Pat. 3,075,264.

The frame members 15 are preferably made of a metal having a very lowcoeflicient of thermal expansion at the operating temperatures of themachine which, in the vicinity of the frame members 15 is approximately200 F. A very suitable metal is a low expansion alloy commonly known asInvar metal having an average coefiicient of thermal expansion between 0F. and 200 F. of about 0.7 1O' which is very low as compared to othermetals generally. Invar is an iron-nickel alloy having approximately 36%nickel. It is important that these frame members substantially retaintheir shape without significant warpage due to any thermal gradient inorder to provide the rigid backup for the mold sections which arethemselves flexible. It is important that the backup means be rigid andthereby provide dimensional stability to the apparatus. If the framemembers 15 did excessively warp, due to a thermal gradient, the range offree movement provided for the flexible mold sections could berestricted too much so that binding of the casting in the mold couldoccur with resultant hampering of advancement of the casting through themachine.

As alternatives for the resilient backup means shown in FIGS. 2, 5, 5a,and 51), for the mold sections 14 and 72, and the corner inserts 27, aconstruction indicated in FIGS. 5c, 5d or 52 can be employed. In FIG.50, a mold section identical to mold section 72 is shown mounted on theframe member 161 similar to frame member 73, except it is machined toaccommodate a plurality of coil type compression springs 162 retained ina plurality of recesses 163 extending in spaced relationship along thelength of the frame member 161. These coil springs 162 react against thebottom ends 163a of the recesses 163 and a separator strip 164 which ispositioned against the inner surfaces 160a of the mold section 160.There is a space 165 between the strip 164 and the frame member 73 topermit the required range of movement of the mold section 160 relativeto the frame member 161 against the resilient pressure of the springs162. With this arrangement, there is no requirement for fluid pressureas the resilient force against the mold section 160. In a similarmanner, the corner inserts 27 can be adapted with suitable springs 162instead of inflatable cushions or tubes 34.

As a further alternative construction, the parts as indicated in FIG. 5dcan be employed. The construction is similar to that which is shown inFIG. 50, except that the recesses 166 shown are larger than the recesses163 shown 13 in FIG. c. This is necessary to accommodate plungers 167which substantially surround the springs 162. These plungers 167 reactbetween the springs 162 and the separator plate 164, instead of havingthe springs bear directly on the separator plate 164. Otherwise theconstruction is the same.

In FIG. Se is still another construction which does not employ the useof springs. Instead, it is another form which employs fluid pressureintroduced through a bore 168 which is substantially similar to bore 76shown in FIG. 5a. However, the frame member 169 shown which supports themold section 160 is provided with a passage 170 connected with the bore168 to receive fluid under pressure from the bore 168. The passage 170is connected by a plurality of smaller passages 171 to a plurality ofcylindrical recesses 172 which contain pistons or plungers 173 guidedfor reciprocation therein. Each plunger 173 is provided with an annularfluid seal 174 to minimize or prevent leakage of fluid from the .passage170 beyond the plungers 173 in the direction of the mold section 160. Aretainer strip 164 is disposed between the plungers 173 and the moldsection 160. It should be evident that the plungers 173 when providedwith fluid under pressure from the passage 170 will cause them to bearwith resilient pressure against the retainer strip 164 to, in turn,transmit the force to the mold section 160. This effect is quite similarto that achieved when employing the inflatable cushion or tube,previously described.

It should be evident that the structure shown in FIGS. 5c, 5d and 5e areall suitable constructions for providing resilient backup means foreither the mold sections 160, or the like, or for the corner inserts 27,or the like.

Although the invention has been described as one relating to aparticular type of vibratory casting machine, some of the principles canstill be applied to other casting machines employing separate moldsections as opposed to the sleeve type mold. Further, although only asingle embodiment and variations thereof of the invention have beenshown and described, it should be clearly understood that the inventioncan be made in many diiferent ways without departing from the true scopeof the invention as defined by the appended claims in which we claim:

1. Apparatus for continuous casting of metal of a type having a cavityextending longitudinally therethrough open at its ends and formed by theinside surfaces of a plurality of discrete mold sections unattached fromeach other located in a substantially closed periphery around the cavitywith said inside surfaces disposed substantially parallel to thelongitudinal axis of the cavity, one of said open ends of said cavitybeing a receiving end through which molten metal can be introduced intosaid cavty and the other of said open ends of said cavity being adischarge end through which said metal can be progressively dischargedfrom said cavity, relatively rigid and inflexible frame members in whichthe mold sections are mounted, said mold sections having suflicientlysmall beam strength that they readily flex when stressed transversely asa beam as compared to the relatively inflexible and rigid frame membersin which the mold sections are mounted.

2. Apparatus as defined by claim 1 characteribed by,

mold section mounting means for supporting said mold sections in theirlocations around the cavity, and resilient backup means applying abackup force reacting between the mounting means and the mold sectionsfor overcoming the tendency of the mold sections to deform whensubjected to the heat of the metal passing through the cavity during thecasting period. 3. Apparatus as defined by claim 2 characterized by,said resilient backup means being in the form of an inflatable pillowwhich provides the backup force upon inflation of the pillow with fluidunder pressure, and means for inflating the pillow with fluid underpressure.

4. Apparatus as defined by claim 2 characterized by, said resilientbackup means being in the form of a thin walled metal tube whichprovides the backup force upon inflation of the tube with fluid underpressure, and means for inflating the tube with fluid under pressure.

5. In apparatus for continuous casting of metal of a type having acavity extending longitudinally therethrough open at its ends and formedby the inside surfaces of a plurality of mold sections located aroundthe cavity with said inside surfaces disposed substantially parallel tothe longitudinal axis of the cavity, one of said open ends of saidcavity being a receiving end through which molten metal can beintroduced into said cavity and the other of said open ends of saidcavity being a discharge end through which said metal can beprogressively discharged from said cavity, relatively rigid andinflexible frame members in which the mold sections are mounted, saidmold sections having sufliciently small beam strength that they arerelatively flexible when stressed transversely as a beam, as compared tothe relatively inflexible and rigid frame members in which the moldsections are mounted, and having a resilient backup means for applying abackup force to react against the mold sections for overcoming thetendency of the mold sections to deform when subjected to the heat ofthe metal passing through the cavity during the casting periodcomprising, said resilient backup means being in the form of-aninflatable tube which provides the backup force upon inflation of thetube with fluid under pressure, and means for inflating the tube withfluid under pressure, said tube being constructed of thin walled metaltubing having walls which readily flex and having fluid-tight endclosures and inletoutlet means connected directly to the means forinflating the tube with fluid under pressure.

6. Apparatus as defined by claim 2 characterized by, said resilientbackup means being in the form of a plurality of compression springsapplying a backup force reacting between the mounting means and the moldsections for overcoming the tendency of the mold sections to deform whensubjected to the heat of the metal passing through the cavity during thecasting period.

7. Apparatus for continuous casting of metal of a type having a cavityextending longitudinally therethrough open at its ends and formed by theinside surfaces of a plurality of mold sections located around thecavity with said inside surfaces disposed substantially parallel to thelongitudinal axis of the cavity, one of said open ends of said cavitybeing a receiving end through which molten metal can be introduced intosaid cavity and the other of said open ends of said cavity being adischarge end through which said metal can be progressively dischargedfrom said cavity, said apparatus having an upper rigid plate and a lowerrigid plate spaced from each other and extending substantially parallelto each other and in a direction transverse to the longitudinal axis ofthe cavity of the apparatus, each mold section having an independentmounting means for its support, each of said mounting means beingmounted to extend radially with respect to the longitudinal axis of thecavity and between said plates to extend parallel to the longitudinalaxis with the upper end of each mounting means secured to the upperplate and the lower end of the mounting means being secured to the lowerplate, guide means on the plates for maintaining the mounting means intheir radial positions, said mounting means being adjustable radially inthe guide means so that the mold sections mounted on the mounting meanscan be adjustably positioned in movement radially of said longitudinalaxis of the cavity.

8. Apparatus for continuous casting of metal of a type having a cavityextending longitudinally therethrough open at its ends and formed by theinside surfaces of a plurality of mold sections located around thecavity with said inside surfaces disposed substantially parallel to thelongitudinal axis of the cavity, one of said open ends of said cavitybeing a receiving end through which molten metal can be introduced intosaid cavity and the other of said open ends of said cavity being adischarge end through which said metal can be progressively dischargedfrom said cavity, mold section mounting means for sup- 15 16 portingeach mold section independently in definite radial 3,321,008 5/ 1967Jones l64--280 X positions relative to the longitudinal axis of thecavity, 3,388,737 6/1968 Buckwalter et al. 164283 each mold sectionmounting means being adjustable 3,364,980 1/ 1968 Loewenstein 164-281radially so that the mold sections can be individually adjustablypositioned to different positions radially of the 5 FOREIGN. PATENTSlongitudinal axis of the cavity. 528,868 5/ 1954 g 65,298 1/1947Denmark. References Cited UNITED STATES PATENTS I. SPENCER OVERI-IOLSER,Primary Examiner 2,195,809 4/1940 Betterton et a1. 16482 10ANNEARAssistantExaminer 3,075,264 1/1963 Wognum 16483 3,237,252 3/1966Ratcliife 164280 16443

